If you are wanting to read a short book in the Old Testament let me recommend the Book of Ruth. It is only 4 chapters long.
Ruth is a young Moabite woman who married a man named Mahlon who was from Bethlehem. Mahlon died leaving his mother Naomi and his wife Ruth alone with no children. Naomi moves back to Bethlehem and Ruth follows. Ruth vows to follow Naomi’s God and serve Naomi. In Bethlehem a man named Boaz who is a close relative to Naomi allows Ruth to pick up left over grain from his field. He even asks his workers to drop extra grain for her to pick up, gives her water, and asks the men to treat her nicely. Now we need to remember that Ruth is a Moabite. Not an Israelite. These two groups of people didn’t normally get along well with each other. But Boaz is gracious to her. Naomi convinces Ruth to lay down beside Boaz in the hope that Boaz will marry her so that Mahlon (her deceased son) can have heirs to continue his name. Boaz seeks out one closer relative to marry her, but this relative refuses so Boaz marries Ruth.
Now what is the purpose for this story?
A few observations I can make are that Ruth being a Moabite is a big deal. And Boaz treats her well, even though she is a foreigner. It appears that this is the proper way for Israel to treat foreigners that God is not asking to be destroyed.
And the last few verses are huge in understanding the importance of this story.
Naomi took the baby and cuddled him to her breast. And she cared for him as if he were her own. The neighbor women said, Now at last Naomi has a son again! And they named him Obed. He became the father of Jesse and the grandfather of David.
This is the genealogical record of their ancestor Perez:
Perez was the father of Hezron.
Hezron was the father of Ram.
Ram was the father of Amminadab.
Amminadab was the father of Nahshon.
Nahshon was the father of Salmon.
Salmon was the father of Boaz.
Boaz was the father of Obed.
Obed was the father of Jesse.
Jesse was the father of David.
— Ruth 4:16-22
The child Ruth has is the Grandfather to David who becomes King of Israel. And it is from David’s lineage that Mary Jesus mother comes from. So we see a connection from a Gentile woman to the King of Israel and then to the King of the Universe.
It can be easy to assume that God hates anyone who is not Jewish up to this point in the Old Testament. But the Book of Ruth is thrown in as a wake up call for us to understand that it is Sin that God hates, not whether we are an Israelite or from another nation. This is also why God gets angry with Israel, their Sin.